A slow-moving brush fire that may have erupted in a makeshift encampment used by transients blackened about a quarter-acre in an overgrown ravine near Sweetwater Reservoir on Monday.

The blaze, which caused no structural damage or injuries, began spreading shortly before 3:30 a.m. off  in Spring Valley, according to Cal Fire.

It took about 25 ground personnel roughly 90 minutes to get the flames contained, said Kendal Bortisser, a fire captain with the state agency.

Investigators were looking into whether the activities of homeless people who frequent the area may have sparked the blaze, Bortisser said.

Chris Jennewein is Editor & Publisher of Times of San Diego.